With increasing industrial development, digitalized office technologies have experienced great growth and are now rapidly gaining in popularity. For example, a diversity of office machines such as copy machines, printers, fax machines and scanners (also referred as single-function peripherals) are utilized to achieve various purposes. The diverse office machines, however, occupy lots of space. Nowadays, a multifunction peripheral having multiple functions in one structural unit, for example the functions of a printer, a scanner, a fax machine and/or a copy machine, is thus developed. As a consequence, the processing capability of the multifunction peripheral is increased and the operative space thereof is reduced. Moreover, the process of assembling the multifunction peripheral is simplified. Generally, a single network line, a single telephone line and a single power line are sufficient to communicate the multifunction peripheral with the computer system. As a consequence, the multifunction peripheral is rapidly gaining in popularity.
For performing the printing operation or the scanning operation, the upper cover of the multifunction peripheral needs to be uplifted and then the document to be printed or scanned is placed on the sensitive platform. Typically, the multifunction peripheral comprises a hinge device or a linkage mechanism between the upper cover and a main body thereof in order for pulling open the upper cover. Since the automatic document feeder and the infrared ray image input device of the multifunction peripheral are usually mounted on the upper cover, the upper cover is very weighty. If the hinge device or the linkage mechanism fails to securely withstand the weight of the upper cover, the upper cover will be undesirably pressed on the main body. The strong impact resulted from the upper cover is detrimental to the electronic components of the multifunction peripheral and the safety of the user or maintenance worker.
Recently, the hinge device is continuously improved in order to increase the supporting force to be exerted on the upper cover. In addition, the hinge device also has the functions of positioning and slowly closing the upper cover.
As known, the conventional hinge device has many components, including for example a cam, an upper body, a lower body, a compressing spring, a spring gliding seat, a fixing pin and the like. For assembling these components, a jig tool is required, and thus the assembling process is complicated and labor-intensive. As a result, the fabricating cost is increased and the hinge device is less competitive.
For assuring the smoothness of opening and closing the upper cover of the office machine and reducing the fabricating cost, there is a need of providing an improved hinge device so as to obviate the drawbacks encountered from the prior art.